This is the 2nd revision of the competitive renewal of the training grant ES-07046 "Training in Biochemical and Environmental Toxicology". The training program encompasses three graduate study concentrations; Molecular and Cellular Toxicology, Environmental Toxicology and General Toxicology. Trainees enter the program with a strong background in the biological and physical sciences. A minimum undergraduate grade point average of 3.0 on a 4.0 scale in the biological and physical sciences and combined verbal and quantitative scores on the GRE of at least 1100 are required for admission into the program. All trainees take core courses in toxicology, biochemistry, pharmacology, pathology, statistics, ethics and elective courses are selected based on trainees' research interests and graduate study concentration. Trainees generally receive their Ph.D. in 4-5 years. This training grant is administered through and is an integral part of the Department of Environmental and Molecular Toxicology. There are 10 preceptors participating in this training program and the major research theme is to understand how toxicants/cellular stressors induce cell responses through the alteration of signal transduction pathways and the regulation of gene expression. The elucidation of how toxicants/cellular stressors are translated into alterations in expression and how the gene products are involved in adaptive and toxic cellular responses is crucial to understanding mechanisms of toxicity at the cell, organ and organism level. Trainees receive state-of-the-art research training in areas including: molecular carcinogenesis, cell cycle regulation, endocrine disruption, oxidative stress, signaling pathways involving MAPK, apoptosis, transcriptional regulation, functional toxicogenomics, regulation and expression of xenobiotic metabolizing enzymes, and chemical exposure assessment. The Department of Environmental and Molecular Toxicology's faculty, funding base, student body, training program and facility all have undergone significant and continued growth. To sustain the growth in training opportunity for graduate students in toxicology, funding of this training grant is requested at the level of five predoctoral trainees for year one, six trainees for year two, seven trainees for year three, and eight trainees for years four and five.